About 15 million people have no pension savings and face a bleak future in retirement, according to a major survey of Britain’s personal finances published this week by the Financial Conduct Authority.

The Financial Lives survey of 13,000 consumers by the FCA, the biggest of its kind, found that 31% of UK adults have no private pension provision and will have to rely entirely on the state in their retirement. The full state pension is £159.55 per week, but that is only available to individuals who have a complete record of national insurance contributions.

Of particular worry is the group of people aged over 50 who are not paying into a pension and have few years left to build one up before they reach their 60s. When the FCA asked why they had made no provision, 32% said it was too late to set one up, 26% said they could not afford it and 12% said they were relying on their partner’s pension.

Auto-enrolment has brought millions of people into pension saving for the first time, but millions of self-employed and part-time workers are not in the scheme.

The figures reveal a big gap between men and women: 33% of men expect to retire with just the state pension, but that rises to 53% among women.

Even among those with a company pension, the survey reveals few people will benefit from a generous “final salary” arrangement, which is based on their income just before retirement. The FCA found that only 16% of working people have a final salary pension, while 41% will have to depend on a “defined contribution” (DC) pension, where the payouts will depend on the vagaries of the stock market.

Most people with DC pensions state that they have relatively little in their pension pot. Around two-fifths have less than £5,000 and only 12% have more than £100,000. Half the people who have so far accessed their DC pension say it is not enough to live on.

People also find it difficult to envisage how long they will live in retirement. The average 55- to 64-year-old said they expected to live until 83, which is a few years below actuarial predictions.

The report notes widespread pension confusion among the public. Four in 10 adults aged 35-44 had no idea how much their company was paying into their pension pot, while a third said they had not given any thought to how they would manage financially in retirement. The FCA cited one respondent, Obedi: “All the information is on the [work] intranet, but I don’t understand it. They try and describe it in layman’s terms and I’m not thick, but you’ve got to know what they are talking about ... the full comprehension of it is difficult.”